Title :
Channel Estimation Based on Divergence Minimization for OFDM Systems with Co-Channel Interference
Author :
Manchón, Carles Navarro ; Fleury, Bernard ; Kirkelund, Gunvor E. ; Mogensen, Preben ; Deneire, Luc ; Sørensen, Troels B. ; Rom, Christian
Author_Institution :
Dept. of Electron. Syst., Aalborg Univ., Aalborg East, Denmark
Abstract :
In this paper, we present a novel approach for pilot-aided channel estimation in OFDM systems with synchronous co-channel interference. The estimator is derived based on the Kullback-Leibler divergence minimization framework. The obtained solution iteratively updates both the desired user´s and the interferer´s channels, using a combination of linear minimum mean squared-error (LMMSE) filtering and interference cancellation, avoiding the complex matrix inversions involved in the full LMMSE channel estimation approach. Estimation of the noise variance is also included in the iterative algorithm, accounting for Gaussian noise and residual interference after each iteration. The estimates of both channels are used at the equalizer to reject the interfering signal, thus mitigating the degradation due to co-channel interference. Simulation results show that the receiver using the proposed estimator performs as good as the one employing the full LMMSE estimator and very closely to a receiver having perfect knowledge of the channel coefficients.
Keywords :
OFDM modulation; channel estimation; cochannel interference; filtering theory; iterative methods; least mean squares methods; minimisation; Gaussian noise; Kullback-Leibler divergence minimization; LMMSE; OFDM system; channel coefficients; equalizer; interference cancellation; iterative algorithm; linear minimum mean squared-error filtering; orthogonal frequency division multiplexing; pilot-aided channel estimation; residual interference; synchronous cochannel interference; Channel estimation; Equalizers; Filtering; Gaussian noise; Interchannel interference; Interference cancellation; Iterative algorithms; Noise cancellation; Nonlinear filters; OFDM;
Conference_Titel :
Communications, 2009. ICC '09. IEEE International Conference on
Conference_Location :
Dresden
Print_ISBN :
978-1-4244-3435-0
Electronic_ISBN :
1938-1883
DOI :
10.1109/ICC.2009.5198818